Air system maintenance?

[kohersh]

I ran across an article in the Sep 16 issue of Family Motor Coach magazine, page 40, titled "Testing Air Brakes". In it the author runs down a procedural checklist, albeit taken from a Spartan chassis manual, and not a Freightliner as is under my 2011 390BH.

The part that caught my eye was the paragraphs that discussed the need to verify the integrity of the air system which included removal of the yellow 1/4" air signal line between the compressor and dryer and the draining of the wet and primary tanks (regardless of a dryer being installed or not). Photos also illustrated color coded wires with pull loops on them for draining the tanks, and the text mentioned conventional tank mounted cocks.
I've been under and around my chassis on multiple occasions and I have yet to 'notice' these in any form, course I wasn't looking for them at the time. So admittedly, in my 18 months and 15k miles of ownership I have never given the brakes a second thought besides verifying the gauge pressures, ride height, and a quick brake check before I take her out. I've never noticed mention of these systems any time its been through a FL shop for annual maintenance either

What do you all do about this? Have I been neglecting a step to proper safety and maintenance?

[gordonsick]

I would be concerned about any air system maintenance procedure that had air lines being disconnected and reconnected unless that procedure was done by a qualified mechanic. But, this is not a recommended procedure in anything that I've read.

There is some discussion of clearing the air system of water in the Freightliner Chassis manual, which is available online at https://secure.freightliner.com/newb...MM_manuals.asp

Other authoritative information on air brakes is in the air brake licensing manuals that are used in Canadian Provinces. Here is the Manitoba link, for example https://www.mpi.mb.ca/en/PDFs/

There are three air drain lines on my Freightliner Custom Chassis, and I think this is common across all the FCC product line. They are in the front wheel wells. If the suspension is aired up, you can usually see the lanyards. Otherwise, turn the front wheels for a better view. Freightliner says you just need to drain them for a brief period. Others say to drain the whole air tank. If possible, have someone pull the lanyard while you watch below for water escaping. Or, do it on a dry patch of pavement to see if any water comes out. If water comes out of any of them, do a longer drain procedure and more frequently.

If you are driving in a humid area, this could be something to worry about. I've never seen water come out in my 15,000 miles of driving.

With the engine running, when the air compressor governor cuts out (about 125 psi), you can hear a release some air from the air dryer. This is expelling any water that collects at the start of the system. On my machine, it seems that this is enough to keep everything dry. That system is called an ADIS (Air Dryer Integrated System).

Reading the Provincial drivers' manuals, you'll note other recommended safety procedures. In theory, you have to check the rear (foundation) brakes daily for excess slack. It is very hard to do this check, since you need to crawl under while the parking brake is released and look for slack in the push rod that actuates the brakes. I did the check once and found no slack at all. Presumably, my slack adjusters are working perfectly. Of course, at some point, they may gum up and be a problem, so an annual check is warranted.

–Gordon

[joet19711]

Just had my 6,000k maintenance done at a Freightliner Service Center and on the two page check list of things to do, one of them : Drain air tanks, which they did. When I was in the Army, (long ago) drove 2 and half and 5 ton, daily after use we drained the air tanks. Draining the tanks daily gets rid of condensate. I have to admit that I have not done that on my Berk.
Maybe some more discussion.

[BamaBob]

Originally Posted by gordonsick

<SNIP>

There are three air drain lines on my Freightliner Custom Chassis, and I think this is common across all the FCC product line. They are in the front wheel wells.

<SNIP>
Presumably, my slack adjusters are working perfectly. Of course, at some point, they may gum up and be a problem, so an annual check is warranted.

Gordon,

Good Advice! I believe I saw somewhere (I may be mistaken) someone saying that these lanyards should be pulled once a month.

As for the slack adjusters, again I believe this is on the annual maintenance 'to do' list.

While I am handy around the coach, I am going to leave the heavy lifting maintenance to the pros - so I am suspecting your annual maintenance trip to Freightliner will take care of the slack adjuster checkup

I DO plan on going to camp Freightliner II in early 2018 - just in time for our annual maintenance, and hopefully I will pick up a few maintenance tips from the tech at Gaffney

Originally Posted by joet19711

Just had my 6,000k maintenance done at a Freightliner Service Center and on the two page check list of things to do, one of them : Drain air tanks, which they did. When I was in the Army, (long ago) drove 2 and half and 5 ton, daily after use we drained the air tanks. Draining the tanks daily gets rid of condensate. I have to admit that I have not done that on my Berk.
Maybe some more discussion.

WOW memories! Duce n a 1/2s & 5 tons - drove them both! you brought back some memories Joe!

[padcarroll]

I just recently noticed a pull cord coming through the frame of my Freightliner/Legacy chassis in the front wheel well. The air tanks are on the other side of the frame.
I drove fire trucks for many years and we had to drain the air tanks daily even after air driers were installed. Condensation will still collect in the tanks with temperature change.

[kohersh]

I re read the manual and poked around some of the FCC documentation i found...looks like its a 6 month routine, 10-15 seconds each lanyard. I still did not find those lanyards however...need a better flashlight

[Phil57]

Originally Posted by padcarroll

I just recently noticed a pull cord coming through the frame of my Freightliner/Legacy chassis in the front wheel well. The air tanks are on the other side of the frame.
I drove fire trucks for many years and we had to drain the air tanks daily even after air driers were installed. Condensation will still collect in the tanks with temperature change.

You should have 3 lanyards. Two in one wheel well and 1 in the other. FL says to drain the tanks every 6 months. I do and have never seen and vapor or actual water drain out.